PRESSURE EFFECT ON VELOCITY OF LIQUID LUMPS IN VERTICAL UPWARD GAS-LIQUID 2-PHASE FLOW

Liquid lump velocities were experimentally determined for vertical upward gas-liquid two-phase flow under a wide range of pressures from near atmospheric pressure to a highly elevated pressure, about 20 MPa. The liquid lumps dealt with here are the liquid slug, huge wave, disturbance wave and ephemeral large wave. Velocities were determined using two sets of signals of time-varying cross-sectional mean liquid holdup which were electrically detected at two axially separated locations of the test tube. The effects of flow parameters such as gas and liquid flow rates as well as pressure on liquid lump velocities are described. The initiation of the transition from plug flow to huge wave flow is also discussed in the presentation of the results.